This invention relates to a process for recovering anthraquinone from tall oil containing anthraquinone and to a novel tall oil product comprising tall oil heads containing anthraquinone.
Recent advances in the paper industry have shown that anthraquinone is an effective digestion additive which improves the paper pulping operation. Improvements in the paper pulping operation include decreased pulping times and improved yields of cellulosic material from the pulping operation. In the manufacture of paper pulp by alkaline processes, such as the Kraft process, black liquor is separated from the cellulosic portion of the wood and concentrated for separation of tall oil soap skimmings therefrom. It now has been determined that the anthraquinone additive added in the pulping operation is found in the tall oil recovered from the black liquor. Because anthraquinone is an expensive product, its recovery from tall oil for reuse in the pulping operation is desirable. The present invention provides a method for recovery of anthraquinone from tall oil in efficient and simple fashion.